Effect of Deposition Time CdSe-TiO2 Nanocomposite Film by Electrophoretic Deposition for Quantum Dot Sensitized Solar Cell

Abstract

Abstract Cadmium selenide (CdSe) nanoparticles have much increased attention in quantum dot-sensitized solar cells (QDSSCs) research for third-generation solar cell. The colloidal CdSe nanoparticles were synthesized by hot injection method in trioctylphosphine oxide as stabilizing solvent and suspended in toluene. CdSe solution was purified by precipitated method to remove some excess of free ligands in the solution and then redispersed in chloroform. Titanium dioxide (TiO2) nanoparticles were purchased and suspended in chloroform. CdSe has been widely used due to its stability and good performance in sensitized devices. In this work, the concentration 4×10 15 dot/cc of CdSe and 3mg/ml of TiO2 nanoparticles in chloroform were mixed. This mixture were deposited on fluorine doped tin oxide conducting glass substrate by electrophoretic deposition (EPD) technique at fixed applied voltage 150V and varying deposition times 80s, 120s and 140s. The deposited films surface were characterized by scanning electron microscope. A complete QDSSC was assembled by using polysulfide electrolyte and Cu2S counter electrodes. Polysulfide electrolyte was prepared from sulphur, sodium sulphide, sodium hydroxide and methanol/deionized water. The power conversion efficiency of the QDSSCs were measured under simulated AM 1.5, 100 mW cm2 illumination. From the J-V measurement, the highest efficiency 7 ×10-3% photoanode with CdSe-TiO2 deposited film at 150V for 80 s.